Macular edema (ME) is a common cause of significant visual loss in a wide variety of ocular conditions. The early detection and classification of ME is of special importance in diabetic retinopathy (DR), the leading cause of new cases of legal blindness among working age Americans. It is important to distinguish between different types of ME in DR, since the optimum treatment depends on position, type, and extension of the ME. Furthermore, the optimum treatment time is when visual acuity not yet significantly affected. Therefore, there is a need for an instrument that is capable of detecting and locating ME in its early stage and of quantifying its extension in three dimensions. [unreadable] The confocal scanning laser ophthalmoscope (CSLO) and optical coherence tomography (OCT) are [unreadable] both clinically usefully retinal imaging techniques developed in the last decade. But neither technique in its current state is an effective clinical tool in managing ME. The long-term goal of this study is to provide a new technique that combines the advantages of CSLO and OCT. [unreadable] During Phase I of this study, the rapid transverse scanning and imaging mode of the CSLO was [unreadable] successfully combined with the increased depth resolution and sectioning capability of OCT. An instrument capable of recording 3D data sets of the human macula was developed. Recording time of a 256x128x64 pixel data set is only 1.2 seconds. The function of the instrument was demonstrated in a feasibility test in normal subjects and patients with ME. Retinal thickness maps were successfully generated and the reproducibility determined. ME could be located and imaged in three dimensions. [unreadable] In Phase II of this study, sensitivity, reproducibility, imaging depth and robustness of the instrument will [unreadable] be further improved. Close to production version prototypes will be developed and constructed. Extensive normative and clinical studies will be performed to optimize the detection and management of ME associated with age related macular degeneration and DR. [unreadable] [unreadable]